The microplastisphere: Biodegradable microplastics addition alters soil microbial community structure and function

Plastics accumulating in the environment, especially microplastics (defined as particles <5 mm), can lead to a range of problems and potential loss ecosystem services. Polyhydroxyalkanoates (PHAs) are biodegradable plastics used mulch films, packaging material minimize plastic waste reduce soil pollution. Little is known, however, about effect microbioplastics on soil-plant interactions, microbial community structure functioning agroecosystems. For first time, we combined zymography (to localize enzyme activity hotspots) with substrate-induced growth respiration investigate PHAs addition structure, growth, exoenzyme kinetics microplastisphere (i.e. interface between microplastic particles) compared rhizosphere bulk soil. We common biopolymer, poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) showed that PHBV was readily by source carbon (C) resulting an increased specific rate more active biomass comparison Higher β-glucosidase leucine aminopeptidase activities (0.6–5.0 times higher Vmax) lower affinities (1.5–2.0 Km) were also detected relative rhizosphere. Furthermore, changed bacterial at different taxonomical levels alpha diversity, well abundance Acidobacteria Verrucomicrobia phyla, untreated soils. Overall, created hotspots where C nutrient turnover greatly enhanced, mainly driven accelerated activity. In conclusion, have alter ecological biogeochemical cycling (e.g., SOM decomposition).